72855640 has 128 divisors (see below), whose sum is σ = 197406720. Its totient is φ = 23846400.

The previous prime is 72855623. The next prime is 72855649. The reversal of 72855640 is 4655827.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 72855640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72855649) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 268705 + ... + 268975.

It is an arithmetic number, because the mean of its divisors is an integer number (1542240).

Almost surely, 2^72855640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72855640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98703360).

72855640 is an abundant number, since it is smaller than the sum of its proper divisors (124551080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

72855640 is a wasteful number, since it uses less digits than its factorization.

72855640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 353 (or 349 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 37.

The square root of 72855640 is about 8535.5515346110. The cubic root of 72855640 is about 417.6582449599.

The spelling of 72855640 in words is "seventy-two million, eight hundred fifty-five thousand, six hundred forty".